A touch panel is an input device that senses the position of a touch made by a user's finger or a tool. Depending on its operating principles, a touch panel is categorized into a resistive type, a capacitive type, an InfraRed (IR) type, a Surface Acoustic Wave (SAW) type, an ElectroMagnetic (EM) type, and an ElectroMagnetic Resonance (EMR) type.
In general, a touch panel includes a sensor layer that senses a touch of an input means (e.g., a finger, a stylus pen, or the like) and that is connected to a controller via wiring electrodes. The controller senses a variation in an output of the touch panel according to a touch of the input means and determines the position of the touch on the touch panel.
The touch panel is typically mounted to an inner surface of a window member that is located above a display. In the touch panel, the sensor layer is disposed in a view area that transmits a screen of the display and the wiring electrodes are disposed in a bezel area defined around the periphery of the view area. The engagement structure of the window member, the wiring electrodes, and the like may be shielded by a light blocking layer formed in the bezel area.
The light blocking layer may be fabricated using a Black Matrix (BM) scheme or a printing scheme. A light blocking layer fabricated using the BM scheme has a very flat, uniform surface, thereby suppressing the occurrence of an open-circuit. However, the color of the light blocking layer is limited to black. Although the light blocking layer may be fabricated using the BM scheme by adding a pigment in order to diversify the design and color of an electronic device, the surface of the light blocking layer may become rough and is vulnerable to formation of foreign materials or bumps after the pigment is dried and hardened. On the other hand, if a light blocking layer is fabricated in the printing scheme, the design and color of an electronic device may be diversified. However, while the printing scheme uses ink and provides various shades other than black, the light blocking layer has a rough surface that may include foreign materials or bumps.
Diverse Color, Material, Finishing (CMF) designs are available to a window member of the related art by forming a light blocking layer. However, electrode wires may not be formed partially or wholly due to surface defects of the light blocking layer. As a result, the electrode wires may have an increased line resistance or may be vulnerable to an open-circuit. If a touch panel is configured in a window member with an increased line resistance or open-circuit of electrode wires, a signal output from a sensor layer may be delayed or lost, thereby decreasing touch sensitivity or an operation speed. Accordingly, there is a need for an improved method for fabricating a touch panel.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.